NTSTATUS
Ext2ReadInode (
IN PEXT2_IRP_CONTEXT IrpContext,
IN PEXT2_VCB Vcb,
IN PEXT2_MCB Mcb,
IN ULONGLONG Offset,
IN PVOID Buffer,
IN ULONG Size,
IN BOOLEAN bDirectIo,
OUT PULONG BytesRead
)
{
PEXT2_EXTENT Chain = NULL;
PEXT2_EXTENT Extent = NULL, Prev = NULL;
IO_STATUS_BLOCK IoStatus;
NTSTATUS Status = STATUS_UNSUCCESSFUL;
ULONG RealSize ;
if (BytesRead) {
*BytesRead = 0;
}
__try {
Ext2ReferMcb(Mcb);
ASSERT((Mcb->Identifier.Type == EXT2MCB) &&
(Mcb->Identifier.Size == sizeof(EXT2_MCB)));
if ((Mcb->Identifier.Type != EXT2MCB) ||
(Mcb->Identifier.Size != sizeof(EXT2_MCB))) {
__leave;
}
if (Buffer == NULL && IrpContext != NULL)
Buffer = Ext2GetUserBuffer(IrpContext->Irp);
/* handle fast symlinks */
if (S_ISLNK(Mcb->Inode.i_mode) &&
Mcb->Inode.i_size < EXT2_LINKLEN_IN_INODE) {
PUCHAR Data = (PUCHAR) (&Mcb->Inode.i_block[0]);
if (!Buffer) {
Status = STATUS_INSUFFICIENT_RESOURCES;
__leave;
}
if (Offset < EXT2_LINKLEN_IN_INODE) {
if ((ULONG)Offset + Size >= EXT2_LINKLEN_IN_INODE)
Size = EXT2_LINKLEN_IN_INODE - (ULONG)Offset - 1;
RtlCopyMemory(Buffer, Data + (ULONG)Offset, Size);
Status = STATUS_SUCCESS;
} else {
Status = STATUS_END_OF_FILE;
}
__leave;
}
//
// Build the scatterred block ranges to be read
//
if (bDirectIo) {
RealSize = CEILING_ALIGNED(ULONG, Size, SECTOR_SIZE - 1);
} else {
RealSize = Size;
}
Status = Ext2BuildExtents(
IrpContext,
Vcb,
Mcb,
Offset,
RealSize,
FALSE,
&Chain
);
if (!NT_SUCCESS(Status)) {
__leave;
}
if (Chain == NULL) {
SafeZeroMemory((PCHAR)Buffer, Size);
Status = STATUS_SUCCESS;
__leave;
}
/* for sparse file, we need zero the gaps */
for (Extent = Chain; Buffer != NULL && Extent != NULL; Extent = Extent->Next) {
if (NULL == Prev) {
ASSERT(Extent == Chain);
if (Extent->Offset) {
SafeZeroMemory((PCHAR)Buffer, Extent->Offset);
}
} else if (Extent->Offset > (Prev->Offset + Prev->Length)) {
SafeZeroMemory((PCHAR)Buffer + Prev->Offset + Prev->Length,
Extent->Offset - Prev->Offset - Prev->Length);
}
if (NULL == Extent->Next) {
if (Extent->Offset + Extent->Length < Size) {
SafeZeroMemory((PCHAR)Buffer + Extent->Offset + Extent->Length,
Size - Extent->Offset - Extent->Length);
}
}
Prev = Extent;
}
if (bDirectIo) {
ASSERT(IrpContext != NULL);
// Offset should be SECTOR_SIZE aligned ...
Status = Ext2ReadWriteBlocks(
IrpContext,
Vcb,
Chain,
Size
);
} else {
for (Extent = Chain; Extent != NULL; Extent = Extent->Next) {
if (!CcCopyRead(
Vcb->Volume,
(PLARGE_INTEGER)(&(Extent->Lba)),
Extent->Length,
PIN_WAIT,
(PVOID)((PUCHAR)Buffer + Extent->Offset),
&IoStatus
)) {
Status = STATUS_CANT_WAIT;
} else {
Status = IoStatus.Status;
}
if (!NT_SUCCESS(Status)) {
break;
}
}
}
} __finally {
if (Chain) {
Ext2DestroyExtentChain(Chain);
}
Ext2DerefMcb(Mcb);
}
if (NT_SUCCESS(Status)) {
if (BytesRead)
*BytesRead = Size;
}
return Status;
}
NTSTATUS
Ext2ReadFile(IN PEXT2_IRP_CONTEXT IrpContext)
{
NTSTATUS Status = STATUS_UNSUCCESSFUL;
PEXT2_VCB Vcb = NULL;
PEXT2_FCB Fcb = NULL;
PEXT2_CCB Ccb = NULL;
PFILE_OBJECT FileObject = NULL;
PDEVICE_OBJECT DeviceObject = NULL;
PIRP Irp = NULL;
PIO_STACK_LOCATION IoStackLocation = NULL;
ULONG Length;
ULONG ReturnedLength = 0;
LARGE_INTEGER ByteOffset;
BOOLEAN OpPostIrp = FALSE;
BOOLEAN PagingIo;
BOOLEAN Nocache;
BOOLEAN SynchronousIo;
BOOLEAN MainResourceAcquired = FALSE;
BOOLEAN PagingIoResourceAcquired = FALSE;
PUCHAR Buffer;
__try {
ASSERT(IrpContext);
ASSERT((IrpContext->Identifier.Type == EXT2ICX) &&
(IrpContext->Identifier.Size == sizeof(EXT2_IRP_CONTEXT)));
DeviceObject = IrpContext->DeviceObject;
Vcb = (PEXT2_VCB) DeviceObject->DeviceExtension;
ASSERT(Vcb != NULL);
ASSERT((Vcb->Identifier.Type == EXT2VCB) &&
(Vcb->Identifier.Size == sizeof(EXT2_VCB)));
FileObject = IrpContext->FileObject;
Fcb = (PEXT2_FCB) FileObject->FsContext;
ASSERT(Fcb);
ASSERT((Fcb->Identifier.Type == EXT2FCB) &&
(Fcb->Identifier.Size == sizeof(EXT2_FCB)));
Ccb = (PEXT2_CCB) FileObject->FsContext2;
Irp = IrpContext->Irp;
IoStackLocation = IoGetCurrentIrpStackLocation(Irp);
Length = IoStackLocation->Parameters.Read.Length;
ByteOffset = IoStackLocation->Parameters.Read.ByteOffset;
PagingIo = IsFlagOn(Irp->Flags, IRP_PAGING_IO);
Nocache = IsFlagOn(Irp->Flags, IRP_NOCACHE);
SynchronousIo = IsFlagOn(FileObject->Flags, FO_SYNCHRONOUS_IO);
if (PagingIo) {
ASSERT(Nocache);
}
DEBUG(DL_INF, ("Ext2ReadFile: reading %wZ Off=%I64xh Len=%xh Paging=%xh Nocache=%xh\n",
&Fcb->Mcb->ShortName, ByteOffset.QuadPart, Length, PagingIo, Nocache));
if ((IsSymLink(Fcb) && IsFileDeleted(Fcb->Mcb->Target)) ||
IsFileDeleted(Fcb->Mcb)) {
Status = STATUS_FILE_DELETED;
__leave;
}
if (Length == 0) {
Irp->IoStatus.Information = 0;
Status = STATUS_SUCCESS;
__leave;
}
if (Nocache &&
(ByteOffset.LowPart & (SECTOR_SIZE - 1) ||
Length & (SECTOR_SIZE - 1))) {
Status = STATUS_INVALID_PARAMETER;
DbgBreak();
__leave;
}
if (FlagOn(IrpContext->MinorFunction, IRP_MN_DPC)) {
ClearFlag(IrpContext->MinorFunction, IRP_MN_DPC);
Status = STATUS_PENDING;
DbgBreak();
__leave;
}
if (!PagingIo && Nocache && (FileObject->SectionObjectPointer->DataSectionObject != NULL)) {
CcFlushCache( FileObject->SectionObjectPointer,
&ByteOffset,
Length,
&Irp->IoStatus );
if (!NT_SUCCESS(Irp->IoStatus.Status)) {
__leave;
}
}
ReturnedLength = Length;
if (PagingIo) {
if (!ExAcquireResourceSharedLite(
&Fcb->PagingIoResource,
IsFlagOn(IrpContext->Flags, IRP_CONTEXT_FLAG_WAIT) )) {
Status = STATUS_PENDING;
__leave;
}
PagingIoResourceAcquired = TRUE;
} else {
if (Nocache) {
if (!ExAcquireResourceExclusiveLite(
&Fcb->MainResource,
IsFlagOn(IrpContext->Flags, IRP_CONTEXT_FLAG_WAIT) )) {
Status = STATUS_PENDING;
__leave;
}
MainResourceAcquired = TRUE;
} else {
if (!ExAcquireResourceSharedLite(
&Fcb->MainResource,
IsFlagOn(IrpContext->Flags, IRP_CONTEXT_FLAG_WAIT) )) {
Status = STATUS_PENDING;
__leave;
}
MainResourceAcquired = TRUE;
}
if (!FsRtlCheckLockForReadAccess(
&Fcb->FileLockAnchor,
Irp )) {
Status = STATUS_FILE_LOCK_CONFLICT;
__leave;
}
}
if ((ByteOffset.QuadPart + (LONGLONG)Length) > Fcb->Header.FileSize.QuadPart) {
if (ByteOffset.QuadPart >= Fcb->Header.FileSize.QuadPart) {
Irp->IoStatus.Information = 0;
Status = STATUS_END_OF_FILE;
__leave;
}
ReturnedLength = (ULONG)(Fcb->Header.FileSize.QuadPart - ByteOffset.QuadPart);
}
if (!IsDirectory(Fcb) && Ccb != NULL) {
Status = FsRtlCheckOplock( &Fcb->Oplock,
Irp,
IrpContext,
Ext2OplockComplete,
Ext2LockIrp );
if (Status != STATUS_SUCCESS) {
OpPostIrp = TRUE;
__leave;
}
//
// Set the flag indicating if Fast I/O is possible
//
Fcb->Header.IsFastIoPossible = Ext2IsFastIoPossible(Fcb);
}
if (!Nocache) {
if (IsDirectory(Fcb)) {
__leave;
}
if (FileObject->PrivateCacheMap == NULL) {
CcInitializeCacheMap(
FileObject,
(PCC_FILE_SIZES)(&Fcb->Header.AllocationSize),
FALSE,
&Ext2Global->CacheManagerCallbacks,
Fcb );
CcSetReadAheadGranularity(
FileObject,
READ_AHEAD_GRANULARITY );
}
if (FlagOn(IrpContext->MinorFunction, IRP_MN_MDL)) {
CcMdlRead(
FileObject,
(&ByteOffset),
ReturnedLength,
&Irp->MdlAddress,
&Irp->IoStatus );
Status = Irp->IoStatus.Status;
} else {
Buffer = Ext2GetUserBuffer(Irp);
if (Buffer == NULL) {
Status = STATUS_INVALID_USER_BUFFER;
DbgBreak();
__leave;
}
if (!CcCopyRead(FileObject, &ByteOffset, ReturnedLength,
Ext2CanIWait(), Buffer, &Irp->IoStatus)) {
if (Ext2CanIWait() || !CcCopyRead(FileObject, &ByteOffset,
ReturnedLength, TRUE,
Buffer, &Irp->IoStatus)) {
Status = STATUS_PENDING;
DbgBreak();
__leave;
}
}
Status = Irp->IoStatus.Status;
}
} else {
ULONG BytesRead = ReturnedLength;
PUCHAR SystemVA = Ext2GetUserBuffer(IrpContext->Irp);
if (ByteOffset.QuadPart + BytesRead > Fcb->Header.ValidDataLength.QuadPart) {
if (ByteOffset.QuadPart >= Fcb->Header.ValidDataLength.QuadPart) {
if (SystemVA) {
SafeZeroMemory(SystemVA, Length);
}
Irp->IoStatus.Information = ReturnedLength;
Status = STATUS_SUCCESS;
__leave;
} else {
BytesRead = (ULONG)(Fcb->Header.ValidDataLength.QuadPart - ByteOffset.QuadPart);
if (SystemVA) {
SafeZeroMemory(SystemVA + BytesRead, Length - BytesRead);
}
}
}
Status = Ext2LockUserBuffer(
IrpContext->Irp,
BytesRead,
IoReadAccess );
if (!NT_SUCCESS(Status)) {
__leave;
}
Status = Ext2ReadInode(
IrpContext,
Vcb,
Fcb->Mcb,
ByteOffset.QuadPart,
NULL,
BytesRead,
TRUE,
NULL );
/* we need re-queue this request in case STATUS_CANT_WAIT
and fail it in other failure cases */
if (!NT_SUCCESS(Status)) {
__leave;
}
/* pended by low level device */
if (Status == STATUS_PENDING) {
IrpContext->Irp = Irp = NULL;
__leave;
}
Irp = IrpContext->Irp;
ASSERT(Irp);
Status = Irp->IoStatus.Status;
if (!NT_SUCCESS(Status)) {
Ext2NormalizeAndRaiseStatus(IrpContext, Status);
}
}
Irp->IoStatus.Information = ReturnedLength;
} __finally {
if (Irp) {
if (PagingIoResourceAcquired) {
ExReleaseResourceLite(&Fcb->PagingIoResource);
}
if (MainResourceAcquired) {
ExReleaseResourceLite(&Fcb->MainResource);
}
}
if (!OpPostIrp && !IrpContext->ExceptionInProgress) {
if (Irp) {
if ( Status == STATUS_PENDING ||
Status == STATUS_CANT_WAIT) {
Status = Ext2LockUserBuffer(
IrpContext->Irp,
Length,
IoWriteAccess );
if (NT_SUCCESS(Status)) {
Status = Ext2QueueRequest(IrpContext);
} else {
Ext2CompleteIrpContext(IrpContext, Status);
}
} else {
if (NT_SUCCESS(Status)) {
if (!PagingIo) {
if (SynchronousIo) {
FileObject->CurrentByteOffset.QuadPart =
ByteOffset.QuadPart + Irp->IoStatus.Information;
}
FileObject->Flags |= FO_FILE_FAST_IO_READ;
}
}
Ext2CompleteIrpContext(IrpContext, Status);
}
} else {
Ext2FreeIrpContext(IrpContext);
}
}
}
DEBUG(DL_IO, ("Ext2ReadFile: %wZ fetch at Off=%I64xh Len=%xh Paging=%xh Nocache=%xh Returned=%xh Status=%xh\n",
&Fcb->Mcb->ShortName, ByteOffset.QuadPart, Length, PagingIo, Nocache, ReturnedLength, Status));
return Status;
}
NTSTATUS
CdCommonWrite (
_Inout_ PIRP_CONTEXT IrpContext,
_Inout_ PIRP Irp
)
/*++
Routine Description:
This is the common entry point for NtWriteFile calls. For synchronous requests,
CommonWrite will complete the request in the current thread. If not
synchronous the request will be passed to the Fsp if there is a need to
block.
Arguments:
Irp - Supplies the Irp to process
Return Value:
NTSTATUS - The result of this operation.
--*/
{
NTSTATUS Status = STATUS_SUCCESS;
PIO_STACK_LOCATION IrpSp = IoGetCurrentIrpStackLocation( Irp );
TYPE_OF_OPEN TypeOfOpen;
PFCB Fcb;
PCCB Ccb;
BOOLEAN Wait;
ULONG SynchronousIo;
PVOID UserBuffer;
LONGLONG StartingOffset;
LONGLONG ByteRange;
ULONG ByteCount;
ULONG WriteByteCount;
ULONG OriginalByteCount;
BOOLEAN ReleaseFile = TRUE;
CD_IO_CONTEXT LocalIoContext;
PAGED_CODE();
//
// If this is a zero length write then return SUCCESS immediately.
//
if (IrpSp->Parameters.Write.Length == 0) {
CdCompleteRequest( IrpContext, Irp, STATUS_SUCCESS );
return STATUS_SUCCESS;
}
//
// Decode the file object and verify we support write on this. It
// must be a volume file.
//
TypeOfOpen = CdDecodeFileObject( IrpContext, IrpSp->FileObject, &Fcb, &Ccb );
// Internal lock object is acquired if return status is STATUS_PENDING
_Analysis_suppress_lock_checking_(Fcb->Resource);
if (TypeOfOpen != UserVolumeOpen) {
CdCompleteRequest( IrpContext, Irp, STATUS_INVALID_DEVICE_REQUEST );
return STATUS_INVALID_DEVICE_REQUEST;
}
//
// Examine our input parameters to determine if this is noncached and/or
// a paging io operation.
//
Wait = BooleanFlagOn( IrpContext->Flags, IRP_CONTEXT_FLAG_WAIT );
SynchronousIo = FlagOn( IrpSp->FileObject->Flags, FO_SYNCHRONOUS_IO );
//
// Extract the range of the Io.
//
StartingOffset = IrpSp->Parameters.Write.ByteOffset.QuadPart;
OriginalByteCount = ByteCount = IrpSp->Parameters.Write.Length;
ByteRange = StartingOffset + ByteCount;
//
// Acquire the file shared to perform the write.
//
CdAcquireFileShared( IrpContext, Fcb );
//
// Use a try-finally to facilitate cleanup.
//
try {
//
// Verify the Fcb. Allow writes if this is a DASD handle that is
// dismounting the volume.
//
if (!FlagOn( Ccb->Flags, CCB_FLAG_DISMOUNT_ON_CLOSE )) {
CdVerifyFcbOperation( IrpContext, Fcb );
}
if (!FlagOn( Ccb->Flags, CCB_FLAG_ALLOW_EXTENDED_DASD_IO )) {
//
// Complete the request if it begins beyond the end of file.
//
if (StartingOffset >= Fcb->FileSize.QuadPart) {
try_return( Status = STATUS_END_OF_FILE );
}
//
// Truncate the write if it extends beyond the end of the file.
//
if (ByteRange > Fcb->FileSize.QuadPart) {
ByteCount = (ULONG) (Fcb->FileSize.QuadPart - StartingOffset);
ByteRange = Fcb->FileSize.QuadPart;
}
}
//
// If we have an unaligned transfer then post this request if
// we can't wait. Unaligned means that the starting offset
// is not on a sector boundary or the write is not integral
// sectors.
//
WriteByteCount = BlockAlign( Fcb->Vcb, ByteCount );
if (SectorOffset( StartingOffset ) ||
SectorOffset( WriteByteCount ) ||
(WriteByteCount > OriginalByteCount)) {
if (!Wait) {
CdRaiseStatus( IrpContext, STATUS_CANT_WAIT );
}
//
// Make sure we don't overwrite the buffer.
//
WriteByteCount = ByteCount;
}
//
// Initialize the IoContext for the write.
// If there is a context pointer, we need to make sure it was
// allocated and not a stale stack pointer.
//
if (IrpContext->IoContext == NULL ||
!FlagOn( IrpContext->Flags, IRP_CONTEXT_FLAG_ALLOC_IO )) {
//
// If we can wait, use the context on the stack. Otherwise
// we need to allocate one.
//
if (Wait) {
IrpContext->IoContext = &LocalIoContext;
ClearFlag( IrpContext->Flags, IRP_CONTEXT_FLAG_ALLOC_IO );
} else {
IrpContext->IoContext = CdAllocateIoContext();
SetFlag( IrpContext->Flags, IRP_CONTEXT_FLAG_ALLOC_IO );
}
}
RtlZeroMemory( IrpContext->IoContext, sizeof( CD_IO_CONTEXT ) );
//
// Store whether we allocated this context structure in the structure
// itself.
//
IrpContext->IoContext->AllocatedContext =
BooleanFlagOn( IrpContext->Flags, IRP_CONTEXT_FLAG_ALLOC_IO );
if (Wait) {
KeInitializeEvent( &IrpContext->IoContext->SyncEvent,
NotificationEvent,
FALSE );
} else {
IrpContext->IoContext->ResourceThreadId = ExGetCurrentResourceThread();
IrpContext->IoContext->Resource = Fcb->Resource;
IrpContext->IoContext->RequestedByteCount = ByteCount;
}
Irp->IoStatus.Information = WriteByteCount;
//
// Set the FO_MODIFIED flag here to trigger a verify when this
// handle is closed. Note that we can err on the conservative
// side with no problem, i.e. if we accidently do an extra
// verify there is no problem.
//
SetFlag( IrpSp->FileObject->Flags, FO_FILE_MODIFIED );
//
// Dasd access is always non-cached. Call the Dasd write routine to
// perform the actual write.
//
Status = CdVolumeDasdWrite( IrpContext, Fcb, StartingOffset, WriteByteCount );
//
// Don't complete this request now if STATUS_PENDING was returned.
//
if (Status == STATUS_PENDING) {
Irp = NULL;
ReleaseFile = FALSE;
//
// Test is we should zero part of the buffer or update the
// synchronous file position.
//
} else {
//
// Convert any unknown error code to IO_ERROR.
//
if (!NT_SUCCESS( Status )) {
//
// Set the information field to zero.
//
Irp->IoStatus.Information = 0;
//
// Raise if this is a user induced error.
//
if (IoIsErrorUserInduced( Status )) {
CdRaiseStatus( IrpContext, Status );
}
Status = FsRtlNormalizeNtstatus( Status, STATUS_UNEXPECTED_IO_ERROR );
//
// Check if there is any portion of the user's buffer to zero.
//
} else if (WriteByteCount != ByteCount) {
CdMapUserBuffer( IrpContext, &UserBuffer );
SafeZeroMemory( IrpContext,
Add2Ptr( UserBuffer,
ByteCount,
PVOID ),
WriteByteCount - ByteCount );
Irp->IoStatus.Information = ByteCount;
}
//
// Update the file position if this is a synchronous request.
//
if (SynchronousIo && NT_SUCCESS( Status )) {
IrpSp->FileObject->CurrentByteOffset.QuadPart = ByteRange;
}
}
try_exit: NOTHING;
} finally {
//
// Release the Fcb.
//
if (ReleaseFile) {
CdReleaseFile( IrpContext, Fcb );
}
}
//
// Post the request if we got CANT_WAIT.
//
if (Status == STATUS_CANT_WAIT) {
Status = CdFsdPostRequest( IrpContext, Irp );
//
// Otherwise complete the request.
//
} else {
CdCompleteRequest( IrpContext, Irp, Status );
}
return Status;
}